package lcr;

public class Test0169 {
}

class Solution0169_1 {
    public char dismantlingAction(String arr) {
        int[] record = new int[26];
        for (int i = 0; i < arr.length(); i++) {
            record[arr.charAt(i) - 'a']++;
        }

        for (int i = 0; i < arr.length(); i++) {
            char c = arr.charAt(i);
            if (record[c - 'a']==1) {
                return c;
            }
        }

        return ' ';
    }
}